php 检查数组PHP中特定值的次数
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Check how many times specific value in array PHP
提问by DobotJr
I have an array named $uid. How can I check to see how many times the value "12" is in my $uid array?
我有一个名为 $uid 的数组。如何检查 $uid 数组中值“12”的次数？
回答by Niet the Dark Absol
Several ways.
几种方式。
$cnt = count(array_filter($uid,function($a) {return $a==12;}));
or
或者
$tmp = array_count_values($uid);
$cnt = $tmp[12];
or any number of other methods.
或任何数量的其他方法。
回答by Rafe Kettler
Use array_count_values(). For example,
使用array_count_values(). 例如，
$freqs = array_count_values($uid);
$freq_12 = $freqs['12'];
回答by MD. Shafayatul Haque
Very simple:
很简单：
$uid= array(12,23,12,4,2,5,56);
$indexes = array_keys($uid, 12); //array(0, 1)
echo count($indexes);
回答by Hammerite
Use the function array_count_values.
使用函数array_count_values。
$uid_counts = array_count_values($uid);
$number_of_12s = $uid_counts[12];
回答by Eineki
there are different solution to this:
对此有不同的解决方案：
$count = count(array_filter($uid, function($x) { return $x==12;}));
or
或者
array_reduce($uid, function($c, $v) { return $v + ($c == 12?1:0);},0)
or just a for loop
或者只是一个 for 循环
for($i=0, $last=count($uid), $count=0; $i<$last;$i++)
if ($uid[$i]==12) $count++;
or a foreach
或 foreach
$count=0;
foreach($uid as $current)
if ($current==12) $count++;
回答by genesis
$repeated = array();
foreach($uid as $id){
if (!isset($repeated[$id])) $repeated[$id] = -1;
$repeated[$id]++;
}
which will result for example in
这将导致例如
array(
12 => 2
14 => 1
)
